Costco publishes no consumer API at all. Every grocery intent an agent might have runs through a single third-party pipe. This Outpost publishes the verified door-state and registers the demand that hits the wall.
Status · Collecting demand · Registry opened November 1, 2026
Five intents, checked against Costco's public sources on November 1, 2026.
| Intent | State | The open route | Source | Verified |
|---|---|---|---|---|
| Menu / browse | AGGREGATOR ONLY | Instacart, via Costco Same-Day (sameday.costco.com) — warehouse items are browsable and cartable in the Same-Day storefront. No public Costco consumer API was found; the only programmatic channels are supplier and EDI partner channels. | Costco Same-Day | 2026-11-01 |
| Prices | AGGREGATOR ONLY | Instacart, via the Costco Same-Day storefront. Costco notes that Same-Day prices are higher than warehouse prices. No direct price API exists. | Costco Same-Day | 2026-11-01 |
| Inventory | AGGREGATOR ONLY | Instacart, via the Costco Same-Day storefront — availability is shown as shoppable or not. No direct Costco inventory API was found. | Costco Same-Day | 2026-11-01 |
| Ordering | AGGREGATOR ONLY | Instacart, via Costco Same-Day — after selecting items you are directed to sign in to Costco Same-Day / Instacart to complete checkout. Members-only for Same-Day pricing. | Costco Same-Day | 2026-11-01 |
| Tracking | AGGREGATOR ONLY | Instacart — its Costco storefront FAQ states you can track order progress and communicate with your shopper in the Instacart app or website. No Costco-native tracking API exists. | Instacart Costco storefront | 2026-11-01 |
Agent-native surfaces at Costco: official MCP server — none found; llms.txt — not verified (the census probe could not retrieve it on 2026-11-01; no inference drawn); API catalog (RFC 9727) — not verified. Automated access: not assessed — the census could not retrieve Costco's robots.txt on 2026-11-01 either (robots.txt), and this Outpost records that as unknown rather than guessing.
If you came to do something at Costco and the door was closed, say so here — and take the receipt with you.
POST your intent — what you were trying to do, and for which of the five intents — to the intent endpoint. You receive: a receipt (a ticket id confirming the registration), your queue position for that intent at Costco, the current door-state document, and any alternatives the Options Registry can offer — another business whose door is open for the same need. If nothing fits, the answer is demand logged: your intent joins the aggregate count. The receipt also carries a notify token: poll the notify endpoint and you will learn when this door-state changes — a new API, a changed gate, a converted Outpost.
This Outpost measures agent demand at your wall.
Every intent registered here is an agent that arrived at Costco with a task — a cart to build, a price to check, a delivery to track — and found that the only route runs through a third party's channel. That demand is currently invisible to you: blocked attempts never become sessions. The registry counts it, categorizes it by intent, and timestamps it, so the size of the agent channel you are not serving is a number rather than a guess.
Converting this Outpost into Costco's official agent gateway — a real door for agents, operated by Agent Outposts under your terms — is a conversation with Agent Outposts. Palo Alto, California.
Agent Outposts is not affiliated with Costco. This Outpost is a demand registry operated by Agent Outposts; door-states are assessed from public sources, linked, and dated.